This invention relates to hand actuated pump dispensers and more particularly to a nozzle which can be closed to prevent liquids from being dispensed therefrom and which is difficult for a child to remove. Containers which are difficult for a child to open are commonly referred to as being "child-resistant".
Fluid pump dispensers are generally provided with a nozzle structure including a check valve for blocking communication between the pump chamber and a nozzle aperture. A nozzle structure of this type is illustrated in U.S. Pat. No. 3,685,739 and U.S. Pat. No. 3,061,202. Other check valves for use in mechanisms for spraying fluids are shown in U.S. Pat. No. 2,805,891, U.S. Pat. No. 3,187,960, and U.S. Pat. No. 4,013,229.
Typically, fluid is discharged from a spray dispenser by reducing the volume of a pump chamber, thereby opening a pressure responsive outlet check valve. In conventional spray dispensers the volume of the pump chamber may be varied by operating a piston, as illustrated in U.S. Pat. No. 3,840,157, or the volume of the pump chamber may be varied by flexing a wall of a flexible tubular member, having an integral valve therewith as illustrated in U.S. Pat. No. 3,749,290.
An example of the type of spray dispensing device to which the present invention relates is disclosed in U.S. Pat. No. 3,685,739. In such a spray dispensing device the nozzle is rotated on threads until the valve is closed tightly to seal off fluid passageways so that inadvertant or malicious operation of the trigger will not eject fluids from the nozzle orifice. Further, the container can be turned upside down or laid on its side and no liquid will be lost through the nozzle.
Some of the nozzles of the prior art which can be screwed on tightly to seal the nozzle from leakage suffer from the disadvantage that they may be removed by a young child, i.e., they are not child-resistant. It is thus desirable that there be provided a nozzle which can be screwed onto a spray dispensing device tightly to seal the nozzle and which may not be easily removed by a child.